CN103050633A - White organic light emitting device - Google Patents
White organic light emitting device Download PDFInfo
- Publication number
- CN103050633A CN103050633A CN2012105059515A CN201210505951A CN103050633A CN 103050633 A CN103050633 A CN 103050633A CN 2012105059515 A CN2012105059515 A CN 2012105059515A CN 201210505951 A CN201210505951 A CN 201210505951A CN 103050633 A CN103050633 A CN 103050633A
- Authority
- CN
- China
- Prior art keywords
- matrix
- layer
- luminescent layer
- level
- lamination
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K50/00—Organic light-emitting devices
- H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
- H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K50/00—Organic light-emitting devices
- H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
- H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
- H10K50/125—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers specially adapted for multicolour light emission, e.g. for emitting white light
- H10K50/13—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers specially adapted for multicolour light emission, e.g. for emitting white light comprising stacked EL layers within one EL unit
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K2101/00—Properties of the organic materials covered by group H10K85/00
- H10K2101/10—Triplet emission
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K2101/00—Properties of the organic materials covered by group H10K85/00
- H10K2101/40—Interrelation of parameters between multiple constituent active layers or sublayers, e.g. HOMO values in adjacent layers
Landscapes
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Electroluminescent Light Sources (AREA)
Abstract
A device for achieving reduced driving voltage and enhanced color stability under high luminance conditions includes an anode and cathode arranged on a substrate to be opposite each other, a charge generation layer between the anode and the cathode, a first stack formed between the anode and the charge generation layer and including a first light emitting layer, and a second stack formed between the charge generation layer and the cathode and including a second light emitting layer in which first and second hosts are doped with phosphorescent dopant, a HOMO level of the first host is greater than that of the second host, and a LUMO level of the first host is greater than an LUMO level of the second host.
Description
The application requires the priority of the korean patent application No.P10-2011-0104337 of submission on October 12nd, 2011, incorporates it into this paper by reference, as setting forth fully at this.
Technical field
The present invention relates to organic luminescent device, and relate more specifically to white organic light emitting device, wherein in luminescent layer, mix and have the matrix (host) of different qualities, even this provides the white organic light emitting device of the color stability that also has the driving voltage that reduces and enhancing under high-brightness environment.
Background technology
In recent years, along with the arrival of information age, the field of display that shows visually electronic information signal is rapidly developed.Correspondingly, have such as the various panel display apparatus of the excellent properties of slim design, low weight and low-power consumption developedly, and replaced rapidly traditional cathode ray tube (CRT).
The detailed example of panel display apparatus can comprise liquid crystal display (LCD), plasma display panel (PDP), Field Emission Display (FED) and organic light emitting apparatus (OLED).
In the middle of above-mentioned panel display apparatus, OLED is not because needing arbitrary source and can realizing that compact device design and accurate color rendering have competitiveness.
In the situation of OLED, the formation of organic luminous layer is essential.
The OLED that proposes is configured to not every pixel organic luminous layer is carried out patterning, but comprises that the lamination (stack) of the organic luminous layer of different colours is stacking to show white light each other.
More specifically, in the white-light organic light-emitting display unit, each layer between negative electrode and the anode is one and deposits on another one, and the mask that need to when forming light-emitting diode, not use.In other words, the use different materials becomes to assign to sequentially to form to comprise the organic film of organic luminous layer and deposits in a vacuum.
The white-light organic light-emitting display unit is Versatile apparatus, for example, its can be used on comprise the glimmer source, LCD is backlight or the full color display unit of colour filter in.
Traditional white-light organic light-emitting display unit is configured such that the lamination of the light of emission different colours comprises respectively hole transmission layer, luminescent layer and electron transfer layer.
Each luminescent layer comprises single-matrix and dopant, and this dopant has the color identical with the light that will launch, and is suitable for by being incorporated into electronics in the luminescent layer and the compound light of launching respective color in hole.
Yet above-mentioned traditional white organic light emitting device has following problem.
Comprise in design in the situation of luminescent layer of single-matrix and dopant, this luminescent layer have narrow can band gap, thereby cause entering electronics in electron transfer layer and the hole transmission layer and the leakage in hole, this has hindered the generation of exciton in the luminescent layer or has increased leakage possibility by the exciton of compound generation.This has caused the deteriorated of the launching efficiency that caused by electron/hole-recombination.
Summary of the invention
Therefore, the present invention is intended to propose a kind of white organic light emitting device, and it has basically been avoided because the limitation of correlation technique and one or more problem that defective causes.
The purpose of this invention is to provide a kind of white organic light emitting device, wherein in luminescent layer, mix and have the matrix of different qualities, this provides the white organic light emitting device of the driving voltage with reduction, and prevent under high brightness conditions Efficiency Decreasing and the variable color that changes according to brightness, thereby obtain the color stability that strengthens.
Other advantage of the present invention, purpose and feature in the following description part are set forth, and to those skilled in the art, during explanation below studying carefully part are become clear, perhaps understand from the practice of inventing.Can realize and obtain these targets of the present invention and other advantage by the structure of in specification and its claim and accompanying drawing, specifically noting.
According to the purpose of invention, in order to obtain these purposes and other advantage, as embody and extensively statement herein, a kind of white organic light emitting device comprises anode and negative electrode, and described anode and negative electrode are arranged on the substrate with toward each other; Charge generation layer, described charge generation layer are formed between described anode and the described negative electrode; The first lamination, described the first lamination is formed between described anode and the described charge generation layer, and comprises the first luminescent layer; And second lamination, described the second lamination is formed between described charge generation layer and the described negative electrode, and comprise the second luminescent layer, in described the second luminescent layer, the first matrix and the second host doped with different transmission properties have dopant, and wherein, the highest occupied molecular orbital of described the first matrix (HOMO) level is higher than the HOMO level of described the second matrix, and wherein, the lowest unoccupied molecular orbital of the first matrix (LUMO) level is higher than the LUMO level of the second matrix.
Described the first matrix and described the second matrix can comprise having 5.0 * 10
-6Cm
2/ sV or higher electron mobility and 5.0 * 10
-8Cm
2The organic material of the hole mobility of/sV.
Described the first matrix and described the second matrix can have respectively 2.7eV or higher can band gap.
The HOMO level of described the first matrix can be than the high 0.05eV to 0.6eV of HOMO level of described the second matrix.
The HOMO level of described the first matrix can be at-5.4eV to the scope of-5.8eV, and the HOMO level of described the second matrix can be at-5.45eV to the scope of-6.0eV.
The LUMO level of described the first matrix can be than the high 0.05eV to 0.6eV of LUMO level of described the second matrix.In this case, the LUMO level of described the first matrix can be at-2.3eV to the scope of-2.8eV, and the LUMO level of described the second matrix can be at-2.35eV to the scope of-3.0eV.
The dopant of described the second luminescent layer can have maximum luminance (PL, Photo Luminance) peak value as phosphorescent dopants in the wave-length coverage of 550nm to 620nm.In this case, the first luminescent layer can blue light-emitting.
Described the first lamination may further include the first hole transmission layer between described anode and described the first luminescent layer and the first electron transfer layer between described the first luminescent layer and the described charge generation layer, and described the second lamination can comprise the second hole transmission layer between described charge generation layer and described the second luminescent layer and the second electron transfer layer between described the second luminescent layer and the described negative electrode.
The triplet energy level of described the second hole transmission layer can be than the triplet energy level of described the second luminescent layer high 0.1eV to 0.4eV.
According to circumstances required, the HOMO level of described the first matrix is higher than the HOMO level of described the second hole transmission layer.
White organic light emitting device can further comprise the cover layer (capping layer) on the described negative electrode.
Be understandable that the general description that the present invention is above and the following detailed description all are schematic and illustrative, and aim to provide the further explanation to the present invention for required protection.
Description of drawings
Accompanying drawing is included to provide a further understanding of the present invention, and is merged in the application and formation the application's a part, and accompanying drawing illustrates embodiments of the present invention, and is used from explanation principle of the present invention with specification one.In the accompanying drawings:
Fig. 1 is that example illustrates the sectional view according to the lamination setting of white organic light emitting device of the present invention;
Fig. 2 be example illustrate according in the second lamination of white organic light emitting device of the present invention can be with the figure of band gap;
Fig. 3 is that example illustrates with white organic light emitting device according to the present invention and compares, traditional phosphorescence unit can be with the figure of band gap;
Fig. 4 be example illustrate according to the phosphorescence unit in the white organic light emitting device of the present invention can be with the figure of band gap;
Fig. 5 is the curve chart that example illustrates the efficient that changes based on the brightness of white organic light emitting device according to the present invention and comparative example;
Fig. 6 is that example illustrates comparative example and according to the curve chart of every electric current and voltage efficient of white organic light emitting device of the present invention; And
Fig. 7 is the figure of level characteristic of composition of the luminescent layer of example example that comparative example and table 1 are shown.
Embodiment
Hereinafter, describe with reference to the accompanying drawings white organic light emitting device of the present invention in detail.
Fig. 1 is that example illustrates the sectional view that arranges according to the lamination of white organic light emitting device of the present invention, and Fig. 2 is that example illustrates according to being with band gap diagram in the second lamination of white organic light emitting device of the present invention.
As shown in figs. 1 and 2, white organic light emitting device of the present invention comprises: anode 110 and negative electrode 130, and it is stacked on the substrate 100 with toward each other; Charge generation layer (CGL) 120, it is formed between anode 110 and the negative electrode 130; The first lamination 210, it is formed between the first lamination 210 and the charge generation layer 120, and this first lamination 210 comprises that the first luminescent layer 115 is with the emission blue light; And second lamination 220, it is formed between charge generation layer 120 and the negative electrode 130, this second lamination 220 comprises the second luminescent layer 125, and in this second luminescent layer 125, phosphorescent dopants mixes with the first matrix 1251 with different transmission properties and the second matrix 1252.
According to circumstances required, if other luminescent layer of the light of emission different colours can be with the phosphor material acting in conjunction of the second luminescent layer transmitting white, just can use other luminescent layer of the light of emission different colours to replace the first luminescent layer of launching blue light.In this case, the first luminescent layer can comprise fluorescence luminescent material or phosphorescent light-emitting materials.
The first lamination 210 also comprises the first hole transmission layer 112 between anode 110 and the first luminescent layer 115 and the first electron transfer layer 116 between the first luminescent layer 115 and the charge generation layer 120.The second lamination 220 also comprises the second hole transmission layer 121 between charge generation layer 120 and the second luminescent layer 125 and the second electron transfer layer 126 between the second luminescent layer 125 and the negative electrode 130.
Anode 110 can be the transparency electrode that is formed by indium tin oxide (ITO), and negative electrode 130 can be formed by the reflective metals such as aluminium (A1).By this configuration, based on illustrated figure, by the luminescent effect of the first and second laminations 210 and 220, image (image) is projection downwards.According to circumstances required, the formation metal of anode 110 and negative electrode 130 can exchange each other, to realize the upwards configuration of projects images.
Although not shown, substrate 100 can be thin film transistor array substrate, comprises select lines intersected with each other and data wire and is formed on select lines and the thin-film transistor of the infall of data wire.
The second hole transmission layer 121 or the first hole transmission layer 112 can have respectively the triplet energy level than the high 0.1eV to 0.4eV of triplet energy level of the second luminescent layer 125 or the first luminescent layer 115.
According to circumstances required, each be used separately as hole transmission layer or electron transfer layer in the first luminescent layer 115 and the second luminescent layer 125 perhaps can comprise a plurality of hole transmission layers or electron transfer layer.Mixed relationship and the quantity of layer can be determined according to the raising of the current efficiency in the lamination of white organic light emitting device.
Example as shown, the first lamination 210 can further comprise the first hole injection layer 111 that is arranged on below first hole transmission layer 112.
Charge generation layer 120 is used for controlling the first lamination 210 located adjacent one another and the charge balance between the second lamination 220, and is called as intermediate connecting layer (ICL).In this case, charge generation layer 120 can be divided into assistance electronic injection is connected hole injection layer 120b to middle connection metal layer 120a and assistance in the first lamination 210 with the centre that the hole is injected into the second lamination 220.Middle connection metal layer 120a is the organic material layer that is doped with the alkalinous metal material with excellent Electron Injection Characteristics.Middle connection hole injection layer 120b is the organic semiconductor layer that contains P type organic material.
Charge generation layer 120 can be individual layer.
The white-light organic light-emitting display unit is configured to by from the blue light of the first lamination emission with from the mixed effect of the phosphorescence of the second lamination emission and transmitting white.
In this case, can be fluorescence from the blue light that is included in the first luminescent layer 115 in the first lamination 210, and also can be phosphorescence.
Consider that the blue phosphor material of current exploitation has the fact of the efficient lower than other phosphor material, such as the mode of the example in the experiment that hereinafter will describe the first luminescent layer 115 is configured to blue fluorescence radiation layer.Have the blue phosphor material suitable with red or green phosphor material efficient if developed, then can use blue phosphor material.
The second luminescent layer 125 that is included in the second lamination 220 can be launched phosphorescence.Based on determining the color of phosphorescence with the first and second matrix 1251 with different transmission properties and 1252 phosphorescent dopants that mix.
The phosphorescent dopants of the second luminescent layer 125 can have maximum luminance (PL) peak value in the wave-length coverage of 550nm to 620nm.For example, phosphorescent dopants can be the dopant of two kinds of different materials, for example, and yellow phosphorus photodopant and green phosphorescent dopants, perhaps red phosphor material and green phosphorescent dopants.Alternatively, phosphorescent dopants can be the homogenous material dopant, for example, and yellowy green phosphorescent dopants or green phosphorescent dopants.
Can further provide cover layer 140 at negative electrode 130.In this case, cover layer 140 is the superiors of white organic light emitting device, and for the protection of the electrode below other organic layer and the cover layer 140, and is used for obtaining the light extraction efficiency or the colour correction that increase.
More specifically, below with reference to Fig. 2 the band gap properties of being with of the first and second matrix 1251 and 1252 is described.
In Fig. 2, what example illustrated the first matrix 1251 in the second luminescent layer 125 and the second matrix 1252 can be with band gap.
In the following description, the energy level that will be described below (that is, highest occupied molecular orbital (HOMO) level and lowest unoccupied molecular orbital (LUMO) level) has negative value.That is to say that although the energy level of lower position has larger absolute value, actual energy level is low.Like this, be the comparison of actual energy level value rather than the comparison of absolute value with what describe.
By relatively being included in the first matrix 1251 with different transmission properties and the second matrix 1252 in the second luminescent layer 125, can consider to design a kind of be configured to so that the HOMO level of the first matrix 1251 and LUMO level respectively greater than HOMO level and the LUMO level of the second matrix 1252.
In this case, when the HOMO level H1 of the first matrix 1251 than the higher (H1＞H2) of the HOMO level H2 of the second matrix 1252, and the LUMO level L1 of the first matrix 1251 is also higher (during L1＞L2) than the LUMO level L2 of the second matrix 1252, can consider to design a kind of being configured to so that band gap can the overlapping each other of the first and second matrix 1251 and 1252, and the second matrix 1252 can with band gap can be a shade below the first matrix 1251 can band gap.
The first matrix 1251 is that electronics domination (dominant) matrix and the second matrix 1252 are hole domination matrix.
The first matrix 1251 and the second matrix 1252 can be by having 5.0 * 10
-6Cm
2/ sV or higher electron mobility and 5.0 * 10
-8Cm
2The organic material of/sV or higher hole mobility forms.That is to say that the first and second matrix 1251 and 1252 have electron mobility rank and the hole mobility rank higher than intended level.Like this, each in the first and second matrix 1251 and 1252 can be electronics domination matrix or hole domination matrix.Although not shown, above-mentioned the first and second matrix 1251 and 1252 have than higher HOMO and the LUMO level of phosphorescent dopants that is included in the luminescent layer 125.Particularly, the first matrix 1251 has than the higher LUMO level of typical matrix that is used for luminescent layer, and this can prevent that electronics and exciton from moving to the second electron transfer layer 126 from the first matrix 1251.In addition, the first matrix 1251 has than the higher HOMO level of typical matrix that is used for luminescent layer, and this has reduced the hole injection barrier at the interface between the second hole transmission layer 121 and the second luminescent layer 125, so that driving voltage reduces and efficient improves.
For example, preferably, the HOMO level of the first matrix 1251 is than the high 0.05eV to 0.6eV of HOMO level of the second matrix 1252.In this case, the HOMO level of the first matrix 1251 at-5.4eV to the scope of-5.8eV, and the HOMO level of the second matrix 1252 at-5.45eV to the scope of-6.0eV.
In addition, preferably, the LUMO level of the first matrix 1251 is than the high 0.05eV to 0.6eV of LUMO level of the second matrix 1252.In this case, the LUMO level of the first matrix 1251 at-2.3eV to the scope of-2.8eV, and the LUMO level of the second matrix 1252 at-2.35eV to the scope of-3.0eV.
The first matrix 1251 and the second matrix 1252 can have respectively 2.7eV or larger can band gap (LUMO level-HOMO level).
Below be that the second luminescent layer 125 of the second lamination 220 comprises the first and second matrix 1251 with different transmission properties and 1252 reason.
The second lamination 220 that two matrix with different transmission properties are provided as the phosphorescence unit with allow the second luminescent layer 125 obtain wide can band gap, to strengthen the compound possibility between electronics and the hole, so that luminous efficiency improves.
In addition, when can with band gap (L2-H2) with as the first lower matrix 1251 of electronics domination matrix and position can band gap (L1-H1) overlapping the time, can realize being easy to the hole is injected in the second luminescent layer 125 as the second matrix 1252 of hole domination matrix.
In other words, for the hole is injected into the second luminescent layer 125 from the second hole transmission layer 121, can reduce traditional debatable hole injection barrier, this can reduce the actual required driving voltage of white organic light emitting device.In this case, can alleviate the degradation in efficiency based on larger brightness, this has guaranteed the luminous efficiency of keeping and obtained raising of color stability under high brightness conditions.
The first matrix 1251 has than the second matrix 1252 better hole transport characteristics, and can have 2.7eV or larger can with band gap (L2-H2) and-5.4eV is to the HOMO level of-5.8eV.
The LUMO level of the second luminescent layer 125, more specifically, the second near near the LUMO level L2 of the second matrix 1252 hole transmission layer 121 is lower, and this has prevented that electronics or exciton from moving to the second hole transmission layer 121 and guaranteeing that electronics or exciton are retained in the second luminescent layer 125 from the second luminescent layer 125.
By the first above-mentioned matrix 1251 can the band gap condition, compare with the configuration of the comparative example shown in Fig. 3 example, can be increased as the HOMO level of the first matrix 1251 of hole domination matrix, this has guaranteed to be easy to from the second hole transmission layer 121 transporting holes.
The triplet energy level of the second matrix 1252 can be 2.7eV or higher.
The hole mobility of the first matrix 1251 can be 5.0 * 10
-8Cm
2/ sV or higher, this has guaranteed to be easy to the second luminescent layer 125 is injected in the hole, and improved with the second luminescent layer 125 in electronics compound.
More preferably, be included in phosphorescent dopants in the second luminescent layer 125 have in the first and second matrix 1251 and 1252 can be with being with band gap in the bandgap range.That is to say the scope (between the LUMO level of the second matrix and the HOMO level of the first matrix) that can must be positioned at band gap L2-H1 of phosphorescent dopants.For example, phosphorescent dopants can have-the LUMO level of 2.8eV ,-the HOMO level of 5.1eV, and the triplet energy level of 2.2eV.Yet what it will be appreciated that is, the invention is not restricted to above-described example, and above-mentioned value can these values be in the first and second matrix 1251 and 1252 can be with the condition in the bandgap range under change.
Fig. 3 be example phosphorescence unit that the comparative example of comparing with white organic light emitting device according to the present invention is shown can be with the figure of band gap.
In the comparative example of Fig. 3, the luminescent layer 50 of phosphorescence unit comprises as the first matrix 51 of electronics domination matrix with as the second matrix 52 of hole domination matrix.Herein, the first matrix 51 whole can with band gap the second matrix 52 can the scope with band gap in.In this case, very large as the HOMO level difference of the HOMO level of the second matrix 52 of hole domination matrix and the second hole transmission layer 40, this has prevented that the hole is injected in the second luminescent layer 50 and has improved driving voltage.
In other words, the first and second matrix with different transmission properties be mixed with each other to obtain phosphorescence unit wide can the system with band gap in, the HOMO level of hole transmission layer 40 and the difference that in fact has between the HOMO level of the second matrix of hole injection effect have caused the high hole injection barrier.
There is not the reference number 60 and 70 of description to represent respectively electron transfer layer and negative electrode herein.Can consider to design so that the LUMO level of electron transfer layer 60 than the lower configuration of LUMO level of the second luminescent layer 50.
In by the configuration of the present invention that mixes the luminescent layer that a plurality of matrix consist of, in order to obtain wide injecting and the electronics of raising and the combined efficiency in hole with band gap, free hole, can consider to design so that the first and second matrix in the second luminescent layer have the configuration of specific relatively HOMO and LUMO level condition.
Fig. 4 be example illustrate according to the phosphorescence unit in the white organic light emitting device of the present invention can be with the figure of band gap.
As shown in Figure 4, below be according to the luminescent layer of phosphorescence of the present invention unit and periphery thereof can band gap.
The second luminescent layer comprises as the second matrix 1252 of electronics domination layer and first matrix 1251 of arranging layer as the hole.The HOMO level H1 of the first matrix 1251 is can be than the HOMO level H2 of the second matrix 1252 higher and can be higher than the HOMO level of the second hole transmission layer 121.These are illustrated different from above-mentioned Fig. 2, and have realized possible expansion execution mode, and it has kept the HOMO level H1 of the first matrix 1251 than the higher requirement of HOMO level H2 of the second matrix 1252.
In addition, in this case, can consider to design a kind of configuration so that the LUMO level L1 of the first matrix 1251 is higher than the LUMO level L2 of the second matrix 1252, and the LUMO level L2 of the second matrix 1252 is higher than the LUMO level of the second electron transfer layer 126.
According to circumstances required, the second hole transmission layer 121 can be designed to bilayer.In this case, being formed by the material with forceful electric power or exciton barrier functionality with the nearer one deck of the second luminescent layer 125 in this bilayer, and formed by the material with stronger hole transport function from the second luminescent layer 125 another layer away from.
The LUMO level L2 of the second matrix 1252 can be less than the LUMO level of the second hole transmission layer 121, and this has prevented that electronics or exciton from moving to the second hole transmission layer 121 from the second luminescent layer 125.
Although what do not have that example illustrates dopant can band gap, according to luminous efficiency, preferably, dopant can with band gap the first and second matrix 1251 and 1252 can band gap within.
Can the band gap condition with what satisfy the first and second above-mentioned matrix by designing the second luminescent layer, according to the present invention, it is possible that following luminescent layer is provided, and this luminescent layer has wide can the injection and higher hole and a plurality of matrix of the combined efficiency between the electronics dispose with band gap, free hole by mixing.
Fig. 5 is the curve chart that example illustrates the efficient that changes based on the brightness of white organic light emitting device according to the present invention and comparative example.
Although Fig. 5 example be illustrated in white organic light emitting device of the present invention and the comparative example all be brightness more high efficiency is lower, what can see is that white organic light emitting device of the present invention shows less efficiency degradation.Particularly, what can see is that under higher brightness, comparative example shows larger efficiency degradation (at about 35000cd/m
2Brightness under, between comparative example and the present invention, produced 5% or more efficiency variance).This means that white organic light emitting device of the present invention has been alleviated efficiency degradation and strengthened color stability when the light time that shows bright color.
Fig. 6 is that example illustrates comparative example and according to the curve chart of every electric current and voltage efficient of white organic light emitting device of the present invention.
As shown in Figure 6, when the current density, J (mA/cm2) under the detection different driving voltage, what can see is that white organic light emitting device of the present invention shows the current density of enhancing under identical driving voltage.
This means that based on the brightness of same hue and identical light, white organic light emitting device of the present invention can be realized Presentation Function under lower driving voltage.Suppose that white organic light emitting device of the present invention as the Organic Light Emitting Diode of display device, then this means the efficient that has strengthened panel.
Experiment as shown in Fig. 5 and 6 is to carry out under white organic light emitting device of the present invention has used the condition of phosphorescence unit of Fig. 4, comparative example has been used the phosphorescence unit of Fig. 3, equally all use blue unit and fluorescence unit, and only arranged the condition difference of the second matrix of matrix as the hole of the second luminescent layer in the phosphorescence unit.
Fig. 7 is the figure of level characteristic of composition of the luminescent layer of example example that comparative example and table 1 are shown.
As listed among table 1 and Fig. 7 and illustrate, if the second matrix 52 can be with band gap complete can band gap overlapping with the first matrix 51, and no matter these matrix have the fact of different transmission properties, then in comparative example, driving voltage is 3.5V, brightness is 74.4Cd/A, and quantum efficiency is 21.2%.That is to say that what can see is, compare with example of the present invention that comparative example all shows deteriorated on all properties.
On the contrary, as shown in Fig. 2 and 4, has following characteristics (wherein, the HOMO level of the first matrix (matrix 1) is greater than the LUMO level of the HOMO level of the second matrix (matrix 2) and the first matrix (matrix 1) the LUMO level greater than the second matrix (matrix 2)) example of the present invention in, what can see is, driving voltage is reduced in the scope of 3.1V to 3.2V, brightness increases to 78.9cd/A (namely from 76.4cd/A, at least than the high 2cd/A of top comparative example), and quantum efficiency than top comparative example high more than 5% (namely, when 21.2% quantum efficiency of the minimum quantum efficiency of 22.2% in these examples and comparative example relatively the time, realized about 5% or more efficient reduction (reduction)).
In the accompanying drawings, what respectively comparative example and these examples are illustrated as dopant can band gap, this dopant can with band gap be limited to the first and second matrix 51 and 52 (or matrix 1 and matrix 2) can the scope with band gap in.
Table 1
Be described below with reference to 1 pair of method of making white organic light emitting device of the present invention of accompanying drawing.
As illustrated among Fig. 1, in the method for making white organic light emitting device of the present invention, at first, form anode 110 at substrate 110.
Then, formed thereon on the substrate 100 of anode 110, sequentially each other the first luminescent layer 115 and first electron transfer layer 116 of stacking the first hole injection layer 111, the first hole transmission layer 112, emission blue light are to form the first lamination 210.
According to circumstances required, the first hole transmission layer 112 can be double-deck, and can further provide the first hole injection layer (not shown) below the first hole transmission layer 112.
Then, form charge generation layer (CGL) 120 at the first lamination 210.
As illustrated, connection metal layer 120a connected hole injection layer 120b with being connected in the middle of charge generation layer 120 can be divided into.
Then, sequentially each other stacking the second hole transmission layer 121, the second luminescent layer 125 and the second electron transfer layer 126 on charge generation layer 120, to form the second lamination 220, first and second matrix that wherein, will have different transmission properties in the second luminescent layer 125 are mixed with phosphorescent dopants.Can on the second electron transfer layer 126 of the second lamination 220, further provide electron injecting layer.
Then, form negative electrode 130 at the second lamination 220.
Here, the triplet energy level of the second hole transmission layer 126 is set to larger than the excited triplet state energy level of the second luminescent layer 125.
As mentioned above, obviously above-mentioned white organic light emitting device of the present invention has following effect.
Phosphorescence unit and unit and fluorescence unit with the stacking white organic light emitting device of cascade (tandem) form in, the luminescent layer of phosphorescence unit comprises two matrix with different transmission properties, obtain wide can band gap.By this way, hole and electronics are limited in the luminescent layer, and this has strengthened restructuring (rebinding) effect and has prevented that exciton from leaking into hole transmission layer or electron transfer layer, the luminous efficiency that is improved.
Further, hole domination matrix can be with band gap and electronics domination matrix can band gap overlapping, and hole domination matrix can with band gap be lower than that electronics arranges matrix can band gap, this has guaranteed that the hole is easy to be injected in the luminescent layer.In this case, eliminate problematic high hole injection barrier, and therefore reduced driving voltage.
In addition, increasing proportional efficiency degradation with brightness can be alleviated, even also can keep color stability under high brightness conditions, realizes the efficient of display floater.That is to say drift (roll-off) phenomenon that to improve the efficiency degradation under the high brightness conditions and change based on brightness.
It will be obvious to those skilled in the art that and in the situation that does not deviate from spirit and scope of the invention, can make various improvement and variation in the present invention.Therefore, the present invention is intended to be encompassed in improvement of the present invention and the variation that provides in claim and the equivalent scope thereof.
Claims (13)
1. white organic light emitting device, described white organic light emitting device comprises:
Anode and negative electrode, described anode and negative electrode are arranged on the substrate with toward each other;
Charge generation layer, described charge generation layer are formed between described anode and the described negative electrode;
The first lamination, described the first lamination is formed between described anode and the described charge generation layer, and comprises the first luminescent layer; And
The second lamination, described the second lamination is formed between described charge generation layer and the described negative electrode, and comprises the second luminescent layer, and in described the second luminescent layer, the first matrix and the second host doped with different transmission properties have dopant,
Wherein, the highest occupied molecular orbital HOMO level of described the first matrix is higher than the HOMO level of described the second matrix, and
Wherein, the lowest unoccupied molecular orbital LUMO level of the first matrix is higher than the LUMO level of the second matrix.
2. device according to claim 1, wherein, described the first matrix and described the second matrix comprise having 5.0 * 10
-6Cm
2/ sV or higher electron mobility and 5.0 * 10
-8Cm
2The organic material of the hole mobility of/sV.
3. device according to claim 1, wherein, described the first matrix and described the second matrix have respectively 2.7eV or higher can band gap.
4. according to claim 3 device, wherein, the HOMO level of described the first matrix is than the high 0.05eV to 0.6eV of HOMO level of described the second matrix.
5. device according to claim 4, wherein, the HOMO level of described the first matrix at-5.4eV to the scope of-5.8eV, and the HOMO level of described the second matrix at-5.45eV to the scope of-6.0eV.
6. device according to claim 3, wherein, the LUMO level of described the first matrix is than the high 0.05eV to 0.6eV of LUMO level of described the second matrix.
7. device according to claim 6, wherein, the LUMO level of described the first matrix at-2.3eV to the scope of-2.8eV, and, the LUMO level of described the second matrix at-2.35eV to the scope of-3.0eV.
8. device according to claim 1, wherein, the dopant of described the second luminescent layer has maximum luminance PL peak value as phosphorescent dopants in the wave-length coverage of 550nm to 620nm.
9. device according to claim 1, wherein, described the first luminescent layer blue light-emitting.
10. device according to claim 1,
Wherein, described the first lamination further comprises the first hole transmission layer between described anode and described the first luminescent layer and the first electron transfer layer between described the first luminescent layer and the described charge generation layer, and
Wherein, described the second lamination comprises the second hole transmission layer between described charge generation layer and described the second luminescent layer and the second electron transfer layer between described the second luminescent layer and the described negative electrode.
11. device according to claim 10, wherein, the triplet energy level of described the second hole transmission layer is than the high 0.1eV to 0.4eV of triplet energy level of described the second luminescent layer.
12. device according to claim 10, wherein, the HOMO level of described the first matrix is higher than the HOMO level of described the second hole transmission layer.
13. device according to claim 1, described device also comprises the cover layer on the described negative electrode.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR20110104337 | 2011-10-12 | ||
| KR10-2011-0104337 | 2011-10-12 | ||
| KR10-2012-0109653 | 2012-10-02 | ||
| KR1020120109653A KR101419249B1 (en) | 2011-10-12 | 2012-10-02 | White Organic Light Emitting Device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103050633A true CN103050633A (en) | 2013-04-17 |
| CN103050633B CN103050633B (en) | 2015-07-08 |
Family
ID=48063205
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210505951.5A Active CN103050633B (en) | 2011-10-12 | 2012-10-11 | White organic light emitting device |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US8884274B2 (en) |
| CN (1) | CN103050633B (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104347807A (en) * | 2013-07-31 | 2015-02-11 | 乐金显示有限公司 | White organic light emitting diode device |
| CN106558651A (en) * | 2015-09-30 | 2017-04-05 | 乐金显示有限公司 | Organic light emitting apparatus |
| WO2017070892A1 (en) * | 2015-10-29 | 2017-05-04 | Boe Technology Group Co., Ltd. | Organic light-emitting diode structure and fabrication method thereof, related display panel, and related display device |
| CN106803540A (en) * | 2015-11-26 | 2017-06-06 | 乐金显示有限公司 | Organic light-emitting display device |
| CN107611276A (en) * | 2017-09-22 | 2018-01-19 | 京东方科技集团股份有限公司 | Organic light emitting diode and display panel |
| US10439158B2 (en) | 2013-12-02 | 2019-10-08 | Semiconductor Energy Laboratory Co., Ltd. | Light-emitting element, light-emitting device, electronic appliance, and lighting device |
| CN110828678A (en) * | 2018-08-10 | 2020-02-21 | 株式会社Lg化学 | Organic light emitting element |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101351512B1 (en) * | 2010-10-25 | 2014-01-16 | 엘지디스플레이 주식회사 | Organic Light Emitting Diode and Method for fabricating the same |
| KR101941453B1 (en) | 2012-09-28 | 2019-01-23 | 엘지디스플레이 주식회사 | Organic light emitting display device |
| DE102013112602B4 (en) | 2012-12-18 | 2020-11-12 | Lg Display Co., Ltd. | White organic light emitting device |
| KR102046157B1 (en) * | 2012-12-21 | 2019-12-03 | 삼성디스플레이 주식회사 | Organic light emitting diode display and manufacturing method thereof |
| KR102101202B1 (en) * | 2013-12-30 | 2020-04-17 | 엘지디스플레이 주식회사 | Organic Light Emitting Diode And Organic Light Emitting Diode Display Device Including The Same |
| KR102106146B1 (en) * | 2013-12-31 | 2020-04-29 | 엘지디스플레이 주식회사 | Organic light emitting display device and method for manufacturing the same |
| KR102574052B1 (en) * | 2015-11-19 | 2023-09-04 | 엘지디스플레이 주식회사 | Organic light emitting display device |
| KR20180041603A (en) | 2016-10-14 | 2018-04-24 | 주식회사 엘지화학 | Electroluminescence device |
| US11895855B2 (en) * | 2019-08-29 | 2024-02-06 | Samsung Electronics Co., Ltd. | Light-emitting device |
| KR102121154B1 (en) | 2019-12-24 | 2020-06-09 | 두산솔루스 주식회사 | Organic electroluminescent device |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1612663A (en) * | 2003-10-27 | 2005-05-04 | 株式会社半导体能源研究所 | Light-emitting element, light-emitting device using the light-emitting element, and electric appliance using the light-emitting device |
| US20050194892A1 (en) * | 2004-03-04 | 2005-09-08 | Universal Display Corporation | OLEDs with mixed host emissive layer |
| CN1953234A (en) * | 2006-10-12 | 2007-04-25 | 友达光电股份有限公司 | White light organic electroluminescence assembly and its application |
| CN100565962C (en) * | 2004-11-17 | 2009-12-02 | 三星移动显示器株式会社 | Small molecular organic electroluminescent display device and manufacture method thereof |
| US20100237338A1 (en) * | 2009-03-23 | 2010-09-23 | Seiko Epson Corporation | Light-emitting element, light-emitting device, display, and electronic apparatus |
| US20110037056A1 (en) * | 2008-12-12 | 2011-02-17 | E. I. Du Pont De Nemours And Company | Photoactive composition and electronic device made with the composition |
| CN102034934A (en) * | 2009-09-29 | 2011-04-27 | 乐金显示有限公司 | White organic light emitting device |
| US20110233457A1 (en) * | 2010-03-23 | 2011-09-29 | Hiroaki Hyuga | Light emitting layer-forming solid material, organic electroluminescent device and method for producing the same |
-
2012
- 2012-10-10 US US13/648,982 patent/US8884274B2/en active Active
- 2012-10-11 CN CN201210505951.5A patent/CN103050633B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1612663A (en) * | 2003-10-27 | 2005-05-04 | 株式会社半导体能源研究所 | Light-emitting element, light-emitting device using the light-emitting element, and electric appliance using the light-emitting device |
| US20050194892A1 (en) * | 2004-03-04 | 2005-09-08 | Universal Display Corporation | OLEDs with mixed host emissive layer |
| CN100565962C (en) * | 2004-11-17 | 2009-12-02 | 三星移动显示器株式会社 | Small molecular organic electroluminescent display device and manufacture method thereof |
| CN1953234A (en) * | 2006-10-12 | 2007-04-25 | 友达光电股份有限公司 | White light organic electroluminescence assembly and its application |
| US20110037056A1 (en) * | 2008-12-12 | 2011-02-17 | E. I. Du Pont De Nemours And Company | Photoactive composition and electronic device made with the composition |
| US20100237338A1 (en) * | 2009-03-23 | 2010-09-23 | Seiko Epson Corporation | Light-emitting element, light-emitting device, display, and electronic apparatus |
| CN102034934A (en) * | 2009-09-29 | 2011-04-27 | 乐金显示有限公司 | White organic light emitting device |
| US20110233457A1 (en) * | 2010-03-23 | 2011-09-29 | Hiroaki Hyuga | Light emitting layer-forming solid material, organic electroluminescent device and method for producing the same |
Non-Patent Citations (3)
| Title |
|---|
| RAMCHANDRA PODE,ET AL: "《Organic light emitting diode-material, process and devices》", 27 July 2011, IN TECH * |
| SUNG HK,ET AL: "Triplet host engineering for triplet exciton management in phosphorescent organic light-emitting diodes", 《JPURNAL OF APPLIED PHYSICS》 * |
| 黄国钧: "charge transport and electroluminescent properties of metal chelate: dependence on deposition rate", 《国立台湾科技大学学位论文全文系统》 * |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI552409B (en) * | 2013-07-31 | 2016-10-01 | 樂金顯示科技股份有限公司 | White organic light emitting diode device |
| CN104347807B (en) * | 2013-07-31 | 2017-06-09 | 乐金显示有限公司 | White OLED device |
| CN104347807A (en) * | 2013-07-31 | 2015-02-11 | 乐金显示有限公司 | White organic light emitting diode device |
| US10439158B2 (en) | 2013-12-02 | 2019-10-08 | Semiconductor Energy Laboratory Co., Ltd. | Light-emitting element, light-emitting device, electronic appliance, and lighting device |
| CN106558651B (en) * | 2015-09-30 | 2019-08-27 | 乐金显示有限公司 | Organic light emitting apparatus |
| CN106558651A (en) * | 2015-09-30 | 2017-04-05 | 乐金显示有限公司 | Organic light emitting apparatus |
| US9978970B2 (en) | 2015-09-30 | 2018-05-22 | Lg Display Co., Ltd. | Organic light emitting device |
| WO2017070892A1 (en) * | 2015-10-29 | 2017-05-04 | Boe Technology Group Co., Ltd. | Organic light-emitting diode structure and fabrication method thereof, related display panel, and related display device |
| US10193104B2 (en) | 2015-10-29 | 2019-01-29 | Boe Technology Group Co., Ltd. | Organic light-emitting diode structure and fabrication method thereof, related display panel, and related display device |
| CN106803540A (en) * | 2015-11-26 | 2017-06-06 | 乐金显示有限公司 | Organic light-emitting display device |
| CN107611276A (en) * | 2017-09-22 | 2018-01-19 | 京东方科技集团股份有限公司 | Organic light emitting diode and display panel |
| CN107611276B (en) * | 2017-09-22 | 2019-03-12 | 京东方科技集团股份有限公司 | Organic Light Emitting Diode and display panel |
| CN110828678A (en) * | 2018-08-10 | 2020-02-21 | 株式会社Lg化学 | Organic light emitting element |
| CN110828678B (en) * | 2018-08-10 | 2023-03-07 | 株式会社Lg化学 | Organic light emitting element |
Also Published As
| Publication number | Publication date |
|---|---|
| US8884274B2 (en) | 2014-11-11 |
| US20130092909A1 (en) | 2013-04-18 |
| CN103050633B (en) | 2015-07-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103050633B (en) | White organic light emitting device | |
| CN102074656B (en) | White organic light emitting device | |
| US9997739B2 (en) | White organic light emitting device | |
| CN101752509B (en) | White organic light emitting device and method for manufacturing the same | |
| KR101419249B1 (en) | White Organic Light Emitting Device | |
| CN103107288B (en) | The display unit of white organic light emitting device and use white organic light emitting device | |
| KR102066090B1 (en) | Organic light emitting display device | |
| KR101786881B1 (en) | White organic light emitting device | |
| US8829504B2 (en) | White organic light emitting device | |
| CN103681760A (en) | Organic light emitting display device | |
| CN104681729A (en) | Organic light emitting device and organic light emitting display device using the same | |
| CN103811531A (en) | Organic light emitting display device | |
| JP2020004970A (en) | Organic light-emitting element, and organic light-emitting display device and display device for vehicle using the same | |
| JP6717886B2 (en) | Organic light emitting device and organic light emitting display device using the same | |
| CN104752624A (en) | White organic light emitting device | |
| CN105304822B (en) | White organic light emitting device | |
| KR101469484B1 (en) | White Organic Light Emitting Device | |
| KR20130074654A (en) | Organic light emitting device | |
| KR101777123B1 (en) | White organic light emitting device | |
| KR101715857B1 (en) | White Organic Emitting Device | |
| CN111916574B (en) | Blue light electroluminescent device, display panel and display device | |
| CN108288677A (en) | Organic luminescent device and its manufacturing method and organic light-emitting display device | |
| KR101777124B1 (en) | White organic light emitting device | |
| KR101786880B1 (en) | White organic light emitting device | |
| CN111200070B (en) | Organic light emitting diode display device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |